n.

1. 补充物，补足物；配对物[（+to/of）]
   Homework is a necessary complement to classroom study.

   家庭作业是课堂教学的必要补充。

2. 足数；全数，整套
   the entire complement of an embassy

   大使馆全体人员

3. （船的）人员定额
4. 【语】补语
5. 【数】余；补；补数；补集
6. 【音】转位音程
7. 【医】（血清中的）补体

vt.

1. 补充，补足；与……相配
   This wine complements the food perfectly.

   用这酒配这些菜肴，相得益彰。

n.

1. a thing that contributes extra features to something else so as to enhance or improve it.
2. the number or quantity that makes something complete:
   we have a full complement of staff.
3. Grammar  a word, phrase, or clause governed by a verb that completes the meaning of the predicate.
   ▸an adjective or noun that has the same reference as either the subject or object (as mad in he is mad or he drove her mad).
4. Physiology  a system of proteins present in blood plasma which combines with antigen–antibody complexes and phagocytes to bring about the destruction of microorganisms and foreign cells.
5. Geometry  the amount by which a given angle is less than 90°.

v.